Sponsored search advertising can provide a significant amount of revenue for web search engines. Sponsored search advertising generally includes matching advertisements to user queries. Typically, the advertisements appear along with the search results on a web page.
An advertiser registers an ad with the system and may provide an ad title, description, and a landing URL, which corresponds to the web page shown when the user clicks on the ad. The advertiser bids on user query terms. The advertisement may be displayed based on the bidded terms. The ads related to the user query may be shown, and the advertiser pays the bidded amount when there is a click on the advertisement.
In the setting described above, ads that are more likely to be relevant may be presented to users higher in the ranking order. One way to rank ads for a query is to use traditional text similarity metrics, such as cosine similarity. However, traditional text similarity metrics are not reliable, because both the query and the ads contain very little text.
One difficulty in assessing the similarity of an ad to a query is the sparseness of information representing both the query and the ad. Another difficulty is that users click on ads for a wide variety of reasons that are not reflected in the similarity of an ad to a query.
In view of the above, it is apparent that there exists a need for an improved system and method to rank advertisements in the context of sponsored search.